This invention relates to a method of recovering blood cell components from whole blood.
Blood analysis is roughly divided into the analysis of blood cell components and plasma components, and however, main analysis is carried out as to plasma components.
The analysis of blood cell components is divided into the analysis based on the outer shape of erythrocyte, leukocyte or the like and the analysis of contents. In the analysis based on the outer shape, for example, in the case of leukocyte, construction, size, normality or abnormality of form and the like of various types of leukocyte, such as cells in various growing stages from blast cells, granulocyte and lymphocyte are investigated. In the analysis of contents, DNA, hemoglobin content of erythrocyte and the like are analyzed. The analysis based on the outer shape are mostly carried out by the observation of whole blood through a microscope, but collection of blood cell components by centrifugation is also carried out. In the case of the analysis of contents, blood cells are collected by centrifugation, and then purified.
When the analysis based on the outer shape is carried out using whole blood, exact observation is difficult. Although the difficulty in observation can be solved by centrifuging it is possible to break the form of blood cells.
An object of the invention is to provide a method for preparing blood cell samples which are deformed little and can be observed easily by a simple means.
The inventors noted that, as the means for separating plasma sample for the analysis of blood cell components, centrifugation requires labor and time, and centrifugation is unsuitable particularly for treating a small number of samples rapidly and for the in site inspection because of requiring a centrifuge and electric power. Thereupon, they have been developing blood filter cartridges which separate plasma or serum from whole blood by filtration using depth filtering material. Japanese Patent KOKAI 9-196911, 9-276631, 10-185780, 10-185909, 10-227788, etc.
Through the development, they found that blood cell components accumulated in the depth filtering material after blood filtration are suitable as the sample for the analysis of blood components based on the outer shape and the like, and can be recovered without or with a small deformation by backwashing the depth filtering material. In the case of hemolyzing blood cells to measure blood cell components, interference of plasma proteins can be removed by washing erythrocytes.
Thus, the present invention provides a method of recovering filtration residues of blood which comprises filtering blood by a blood filtering device comprising a blood filtering material which is a depth filtering material and a holder which contains the blood filtering material and has a blood inlet and filtrate outlet, after finishing the filtering blood, feeding aqueous liquid from the filtrate outlet to recover the filtration residues accumulated in the blood filtering material.
It is also effective to remove proteins by washing blood cells prior to the backwaching.